The present invention relates to a dust trap and valve for controlling flow through the dust trap, and more particularly to an eccentric mounting of an operating lever or arm with respect to the valve flap to facilitate opening of the valve flap with relatively lower effort and torque.
Dust traps of the type herein referred to have been used for years in collection systems such as bag houses wherein a valve seat and matching valve flap closes a dust collecting zone, as beneath a series of vacuum bags, and the valve flap is opened from time to time to dump the contents collected above the flap. In the usual operation of such devices and as set forth in the above noted companion applications, the disclosures of which are incorporated herein by reference and also in my previously issued U.S. Pat. No. 3,257,054 entitled DUST TRAP AND VALVE THEREFOR, there is a substantial pressure differential across the valve flap when closed which can call for the use of substantial force to break the vacuum and pull the valve flap away from its seat.
It is the purpose of this invention to so position the flap actuating lever with respect to the flap in an eccentric or off-center manner so as to initially lift only one edge of the valve flap plate while the other remote edge therefrom serves as a fulcrum, thereby to initially break the vacuum prior to full opening and swing removal of the valve plate.
As a consequence, the torque required on the operating shaft for opening the valve is reduced and the accompanying power requirements for the operating motor or manual actuator are substantially lessened.